https://apolloinrealtime.org/13/?t=058:06:19&ch=21The set-up for this will be familiar to anyone who has seen the film Apollo 13: Jim Lovell asks the ground to check his arithmetic to ensure that he's correctly transferred the guidance alignment from the CM into the LM. (You can hear this at 058:04:03.)
In the film you can see the line of controllers in the Trench frantically scribbling out calculations and immediately giving the thumbs up. In actuality, Glynn Lunney had to chase Guidance about it... three times.
And then who actually did the checking? That voice from the backroom is as clear as a bell: it's Jack Garman, the backroom hero of Apollo 11.
"OK, we have LGC data, look at the (?), and when you're satisfied, as we are, tell him that his arithmetic is good."